Early reversal of weight gain is essential to prevent insulin resistance!

"The present study demonstrates for the first time that intentional weight gain within the normal range of subjects who are lean to begin with leads to a significant elevation of basal plasma insulin, C-peptide, and glucose concentrations, whereas after ingested or injected stimuli only insulin levels were raised. An increase of insulin resistance is indicated by HOMA-IR in the basal state, by comparable glucose levels despite higher insulin concentrations following oral stimulation, and by a reduced rate of glucose disposal despite higher insulin concentrations during a glucose clamp at physiological hyperglycemia."

"The present data favor the concept that at this early stage of weight gain changes of secretory products from fat cells, incretin hormones of the intestinal tract, or metabolic factors such as fatty acids have a substantial influence on basal and postprandial hepatic insulin metabolism, whereas increased β-cell function plays a minor role and is primarily restricted to the basal state."

http://ajpendo.physiology.org/content/294/3/E568.full.pdf+html